The last time I used it, SLIME integration for Clojure was very slick. It was a while back so there were a fair number of moving parts to align, but I'd guess that has gotten better.
It is worth doing, especially if you've never used another integrated Lisp environment, but I wouldn't recommend laying it on top of learning Clojure. I'd say learn Clojure first, then try out emacs and the emacs integration.